Enclosed motor-compressor unit



March 1, 1960 H. SOUMERAI ENCLOSED MOTOR-COMPRESSOR UNIT Filed July 9,1958 FIG. I

G HENRI SOUMERAI United States Patent O ENCLOSED MOTOR-COMPRESSOR UNITHenri Soumerai, Springfield, Mass., assignor to Worthington Corporation,Harrison, N.J., a corporation of Delaware Application July 9, 1958,Serial No. 747,525

Claims. (Cl. 230-206) serious operational difficulties and particularlyin heremetic units of the horizontal type.

First, the return of lubricant from the motor compartment to thecompressor compartment is arrested because operational characteristicsof the unit tend to build up a higher pressure in the compressorcompartment than existing in the motor compartmentthe compartments beingsubstantially sealed from each other.

Coincident with the foregoing pressure build-up, in the compressioncompartment, is the increase in oil level in the motor compartment. As aconsequence the 'motor becomes oil flooded and if the condition isallowed to prevail the compressor becomes oil starved.

Various systems have been incorporated into the construction ofheremetic motor-compressors to relieve the arresting influence that thehigher gas pressure, in the compression compartment, has on thelubricant collected in the motor compartment.

One such system is disclosed in United States Patent 2,673,026 andprovides a hermetic motor compressor with means for reducing thepressure in the compression compartment below the pressure in the motorcompartment whereby lubricant then returns from the motor compartment tothe compression compartment.

An analysis of the foregoing patent indicates that the problem relatingto oil build-up in the motor compartment is solved with the systemdisclosed therein. However, another difliculty is presented andparticularly in a compressor wherein the motor is cooled by the workingfluid of the system in which the unit is operating. Flow of the hotsystem gases from the compression compartment through the shaft and outthe pump located in the shaft at the outboard end of the motor compart-.ment tends to adversely affect the motor temperature, ,because thesehot gases, expelled at the outboard end of the motor compartment, thenmake a return pass through .the motor to further increase thetemperature thereof.

The present invention meets the problem of reducing the arrestinginfluence that the higher gas pressure, in the compression compartment,has on the, lubricant col- "lected in the motor compartment and inaddition in such amanner so as not to interfere with the'cooling actionthat the system fluid has on the motor of the unit.

Said another way, hot gases are ejected from the compressioncompartment, and as described hereinafter, for

passage to the suction manifold in such a fashion that "ice they areprecluded from interfering with the motor cooling eflfect that thesystem fluid has thereon.

Accordingly, it is one object of this invention to provide a hermeticmotor-compressor with novel ejector means that remedy the foregoingobjections.

It is another object to provide an improved enclosed motor-compressorunit.

With the foregoing objectives in view, and others as may appear from theaccompanying specification, the

invention consists of various features of construction and combinationof parts, which will be first described in connection with theaccompanying drawings, showing an enclosed motor-compressor embodyingthe novel ejector means, and the features of the invention will bespecifically pointed out in the claims.

In the drawings:

Figure 1 is a longitudinal view in section of the enclosedmotor-compressor embodying the invention.

Figure 2 is a sectional view taken on line 22 of Figure 1 showing theejector means.

Referring more particularly to the drawings, Figure 1 thereofillustrates an enclosed motor-compressor unit generally designated 1embodying the present invention. The motor-compressor unit is of theusual type and comprises a casing 2 divided into the usual compressioncompartment generally designated 3 including the compression means 5 anda driving compartment generally designated 4 including a driving means 6by a partition means 7 which maintains the respective compartmentssubstantially sealed from one another. Means taking the form of theusual crankshaft 8 is provided for interconnecting the compression means5 to the driving means 6, the compression means receiving power from thedriving means as is customary and in order to circulate the workingfluid of the refrigeration system (not shown) with which it isassociated.

Referring to Figure 1 in greater detail, a cylinder 26 is formed in thecompression portion 3 which is usually integral with the casing 2. Theusual cylinder head 27 is secured to the casing 2. Any suitablearrangement of intake and exhaust valves for the working fluid may beemployed. In order to compress the working fluid I have provided apiston 28 adapted to reciprocate in the cylinder 26. The drivingmechanism for the piston 28 comprises a connecting rod 29 driven fromthe crankshaft 8 which turnsin bearings 30 and 31 suitably retained inthe partition 7. Bearing 31 is suitably spaced from the driving means 6to provide a portion 32 in the low pressure zone of the drivingcompartment adapted to accommodate the ejector means 14 which isdescribed in detail hereinafter.

In the normal application working fluid from the low side of therefrigeration cycle is received by the compressor through an inlet 9provided in the driving compartment 4 which is divided into a first zone10 and a second zone 11 by the driving means 6. This fluid is thenpassed in heat exchange relationship with the motor 6 to the suctionmanifold 12, usually formed in the first zone and then to thecompression means 5 for passage to the high side of the cycle.

It is evident that passage of the refrigerant through the motor willcause a resultant pressure drop in the gas flowing therethrough. As aconsequence the zone receiving the gas that has been passed through themotor will be at a lesser pressure than the zone receiving the gas fromthe low side of the cycle. In the example shown, the first zone 10 willbe at a lesser pressure than the second zone 11. However, it is notintended to limit the scope of the invention to this relationshipbecause the zone receiving the gas from the low side of the cycle willbe at a higher pressure than the zone receiving the gas that has passedthrough the motor. 1

"posed in the zone of lesser pressure and preferably mounted on theportion 32. of the shaft 8 formed between the bearing liliand drivingmeans 6 and in communication with a passage means formed therein and toprovide operative communication between the cornpression compartment andthe zone of lesser pressure (the first zone) formed in the drivingcompartment. In

addition to providing a pressure differential between the first zone Itand the compression compartment ,2 to

' permit return of lubricant to the compression compartment throughmeans shown as 'a'check valve 15' in partition 7, which means providescommunication between the zone of lesser pressure and the compressioncompartment 3, disposition of the ejector means 14 in the zone of lesserpressure also provides direct passage of the hot compression gases tothe suction inlet 12 to eliminate the heating effect that they had inthe past on the motor of the unit.

The ejector 14 is shown as a cast impeller including passage channels 16and a hub portion 17 provided with a cavity 18 for accommodating asealing member such as an O-ring 19. However, it is not intended tolimit the ejector to this form as it may comprise a hub mounted betweenthe bearing 31 and driving means 6 and include tubes 'or discs forejecting gas from the compression compartment 3.

Two similar impeller members are connected together by fastening means,such rivets it), with the channels 16 matching to provide flow definingpassage means. With Q-rings 17 and 17 mounted in each impeller theejector assembly is pressed onto the portion of the crankshaft 8 in thezone of lesser pressure and upto the bearing housings 21 which serves tosealably position the ejector over the groove 22 formed about the outerperiphery of shaft 8 and in communication with a hole 23 also in thecrankshaft 8 which communicates with a longitudinal hole 24 in theshaftwhich is operatively connected to a radial hole 25 formed in the portionof the crankshaft 8 housed in the compression compartment 3.

Accordingly, with this construction and during operation of thecompressor the ejector 14 mounted on the shaft8 and in-communicationwith the compression compartment through passage means 15 creates adifferential pressure between the compression compartment 13 and thezone of lesser pressure 10 by ejecting the gases building up in thecompression compartment to the zone of lesser pressure 10 and directlyto the'suction manifold 12. As a consequence, motor cooling is notaffected and the pressure in the compression compartment is lowered topermit return of lubricant collected in the driving compartment to thecompression compartment through the check valve 15 in the partition 7.

It will be understood that the invention is not to be limited to thespecific construction or arrangement of parts shown, but that they maybe widely modified within the invention defined by the claims.

What is claimed is:

1. In a compressor of the hermetic type including a casing, partitionmeans for dividing the casing into a driving compartment and acompression compartment, compression means in said compressioncompartment and driving :means in the driving compartment, shaft meansin the casing operatively interconnecting said compression means toisaiddriving means, said driving .means dividingthe :driving compartmentinto a-first zone adjacentthe'comhaving an inlet and an outlet, andmeans connecting said inlet with said compression compartment to howfluid therefrom into said first zone and means in the partitionproviding operative communication between the driving compartment andthe compression compartment whereby lubricant flows from the drivingcompartment to the compression compartment.

2, In a compressor of the hermetic type including a casing, partitionmeans for dividing the casing into a driving compartment and acompression compartment, compression means in said compressioncompartment and driving means in the driving compartment, shaft means inthe casing operatively interconnecting said compression means to saiddriving means, said driving means dividing the driving compartment'intoa first zone adjacent the compression compartment and a second zone,said first zone including a suction compartment for communicating saidfirst zone withsaid compression means, means for said shaft means topass fluid from said compression compartment to said suctioncompartment, said last mentioned means comprising a passageway in saidshaft and opening at one end in said compression means and at the otherend in said first zone, an ejector in said first zone and mounted on theportion of said passageway opening in said first zone whereby fluid isflowed from the compression compartment to the suction compartmentduring operation of, the compressor, and means in the easing providingoperative communication between the driving compartment and thecompression compartment whereby lubricant fiows from the drivingcompartment to the compression compartment.

3. In a compressor of the hermetic type including a casing, partitionmeans including a bearing housing and said partition means for dividingthe casing into a'driving compartment and a compresson compartment,compression means in said compression compartment and driving means insaid driving compartment, shaft means in said casing and disposed insaid bearing housing to operatively interconnect said compression meansto said driving means, said driving means dividing the drivingcompartment into a first zone adjacent the compression compartment and asecond zone, the first zone including a suction compartment forcommunicating said first zone with the compression means, passage meansin said shaft means and for communicating the compression compartmentwith said first zone and said passage means opening at one end into saidfirst zone between said bearing housing and said driving means, ejectormeans mounted onsaid shaft and in communication with the end of thepassage means opening into said first zone whereby on operation of saidcompressor fluid is passed from the compression compartment to saidsuction compartment through said ejector means, and means in the casingproviding operative communication between the driving compartment andthe compression compartment whereby lubricant flows from the drivingcompartment to the compression compartment.

4. In a compressor of the hermetic type including .a casing, partitionmeans including a bearing housing and said partition means for dividingthe easing into a driving compartment and a compression compartment,compression means in said compression compartment and driving means insaid driving compartment, a shaft in said casing and disposed in saidbearing housing to operatively interconnect said compression means tosaid driving means, said driving means, dividing the driving compartmentinto a first zone adjacentsaid compression compartment and aseco'ndzone, the first zone including a suction compartment "forcommunicating said first zone with the compression means, means for saidshaft 'topass fluid "from said compression compartment tosaid suctioncompartment, said last mentioned means comprisingalldngitudinal'passageway in said shaft having radial ports at therespective ends thereof, one of said ports opening-into theiCOlIlPiCSSlOH compartment,-the other-port opening into said first zonebetween said bearing housing and said driving means, an ejector mountedon said last mentioned port whereby fluid is flowed from the compressioncompartment to said suction compartment during operation of saidcompressor, and vent means in the partition means providing operativecommunication between the driving compartment and the compressioncompartment whereby lubricant flows from the driving compartment to thecompression compartment.

5. The compressor of claim 4 wherein the ejector corn- 10 2,673,026

prises separate discs including channels therein and having hub portionsincluding a cavity through the inner periphery of the hub, said separatediscs being connected together so that the channels form passageways incommunication with the port in said shaft and sealing means in fluidsealing relation with the shaft.

References Cited in the file of this patent UNITED STATES PATENTSGerteis Mar. 23, 1954

